Question

sort each of the following examples into either the balanced or unbalanced category. an apple hanging on a tree. a skier coming down a mountain. a lamp sitting on a desk. a painting hanging on the wall. a car accelerating from the start line. a soccer ball after it was kicked. a train moving at a constant speed. a parachutist falling to the ground. is your work saved? go back to lab room

Explanation:

Step1: Recall force - balance concept

Balanced forces result in no change in motion (stationary or constant - speed motion), unbalanced forces cause a change in motion.

Step2: Analyze each example

• An apple hanging on a tree: Gravity and the tension in the stem balance, so it's stationary. Balanced force.
• A skier coming down a mountain: Gravity, friction, and normal force are not balanced as the skier is accelerating. Unbalanced force.
• A lamp sitting on a desk: Gravity and the normal force from the desk balance. Balanced force.
• A painting hanging on the wall: Gravity and the tension in the hanging mechanism balance. Balanced force.
• A car accelerating from the start - line: Engine force is greater than resistive forces, so it's accelerating. Unbalanced force.
• A soccer ball after it was kicked: Air resistance and gravity act on it, and it's in motion with a changing velocity. Unbalanced force.
• A train moving at a constant speed: Driving force and resistive forces balance. Balanced force.
• A parachutist falling to the ground: Gravity and air resistance are usually not balanced as the parachutist is moving. Unbalanced force.

Answer:

Balanced Forces: An apple hanging on a tree, A lamp sitting on a desk, A painting hanging on the wall, A train moving at a constant speed
Unbalanced Forces: A skier coming down a mountain, A car accelerating from the start line, A soccer ball after it was kicked, A parachutist falling to the ground